This invention relates to an improved coupler assembly and more particularly to an assembly for detachably coupling an implement such as a bucket, grapple, rake and the like to the dipper stick of a machine such as an excavating machine.
In the construction, mining and other industries involved in bulk material handling, it has been a common practice to provide an assembly mountable on the dipper stick of a machine such as an excavating machine for quickly coupling and uncoupling different implements such as buckets, grapples, rakes and the like to permit a variety of work functions to be performed without incurring extensive downtime of the machine which results in lower productivity. Although there are many of such coupling assemblies in the prior art which are operable to readily couple and uncouple such implements, it has been found that such assemblies are not greatly desirable for a number of reasons. Often, they are complicated in design, difficult and expensive to manufacture and install and/or require extensive modification of the dipper stick of the machine and/or the implements to be coupled to the dipper stick. They further often add weight to the end of the dipper stick which correspondingly reduces the lift capacity of the machine and/or increase the displacement of the implement from the dipper stick which correspondingly reduces the penetrating force of the coupled implement. It thus has been desirable to provide a simple coupler assembly which may be readily mountable on a conventional dipper stick of a machine and detachably connected to a number of conventional implements without extensive modification of such dipper stick and implements.
Many conventional excavating machines generally are provided with a wheel or track mounted chassis, a support platform mounted on such chassis and usually swingable about a vertical axis, a boom pivotally connected to such platform for pivotal movement about a horizontal axis, a first fluid actuated cylinder assembly operatively interconnecting the machine platform and the boom, a handle or dipper stick pivotally connected to the end of such boom, a fluid actuated cylinder assembly operatively interconnecting the boom and the dipper stick, and an implement pivotally mounted on the end of the dipper stick. Typically, the implement is operable to pivot about a horizontal axis and is actuated by a fluid actuated cylinder assembly operatively interconnecting the dipper stick and the implement. Such actuating assembly conventionally has consisted of a cylinder member having a base end connected to an upper side of the dipper stick, a rod member pivotally connected to a pair of support links pivotally connected to sides of the dipper stick adjacent its free end and a pair of actuating links interconnecting the support links with the implement. Normally, the implement is provided with a pair of mounting brackets on an upper wall thereof, in which there is provided a pair of spaced pins for connecting the implement to the end of the dipper stick and the free ends of the actuating links. With the implement thus attached, it will be appreciated that by operating the various fluid actuated cylinder assemblies, the front end of the machine may be swung, the boom and dipper stick may be raised and lowered and the implement, often an excavating bucket, may be curled and uncurled relative to the dipper stick, in performing various work functions.
In such an arrangement, the present invention contemplates providing brackets on such implements having pairs of opposed pin receiving recesses or modifying the mounting pin brackets of conventional implements by removing the connecting pins therefrom and cutting away the upper portions of the brackets to provide an upperwardly opening recess having a pair of opposed recessed portions consisting of portions of the connecting pin seats, utilizing the end of the dipper stick to provide a first connecting pin insertable into one set of the opposed recessed portions of the implement mounting brackets, and providing a second connecting pin rotatably mounted in the actuating links and insertable in the other set of opposed recessed portions of the implement brackets, and a pair of spacer links rigidly connected at one set of ends thereof to the second connecting pin for pivotal movement therewith and attachably connectable at the other set of ends thereof to the first connecting pin.
With the spacer links attached to the first connecting pin and the connecting pins inserted in the implement bracket recesses, such spacer links cooperate with a portion of the dipper stick and the support and actuating links to form a four bar linkage, and by simply operating the cylinder assembly interconnecting the dipper stick and the support links, the implement may be curled and uncurled, in the conventional manner. With the spacer links detached from the first connecting pin, allowing a collapse of the linkage, the boom and dipper stick may be maneuvered and the cylinder assembly interconnecting the dipper stick and the support links may be operated to displace the connecting pins relative to each other and thus permit the connecting pins to be inserted into and withdrawn from the implement bracket recesses to correspondingly couple and uncouple implements to the dipper stick.